Toxicology Commons^™

Solvants Verts : Fondements, Santé, Sécurité, Environnement Et Substitution, Denis Bégin, Caroline Couture, Michel Gérin, Maximilien Debia

Rapports de recherche scientifique

L’utilisation de solvants dans de nombreuses applications (dégraissage, nettoyage, décapage, imprimerie, peintures, adhésifs, fabrication de produits pharmaceutiques) constitue une préoccupation majeure. En effet, un grand nombre d’entre eux sont associés à des effets nocifs, tant sur la santé et la sécurité des travailleurs (brûlure, cancer, dermatite, encéphalopathie, fœtotoxicité, polynévrite) que sur l’environnement et la santé de la population générale (précurseurs de smog, pollution des eaux, couche d’ozone). Par ailleurs, de plus en plus d’entreprises veulent prendre le virage vert, c.-à-d. faire en sorte que leurs activités et leurs produits s’inscrivent dans la démarche du développement durable. C’est dans ce contexte …

The Effect Of Seasonality On Yellow Perch Ecology And Ecotoxicology Within Lake Manganese, Bailey Duxbury

Dissertations, Master's Theses and Master's Reports

Seasonality is a consistent component of aquatic ecosystems yet most fish biological and ecotoxicological studies commonly employ field sampling protocols focused during the warm open water season with minimal emphasis placed on winter sampling, especially for north-temperate latitude ecosystems. Such strategies limit our understanding of poikilotherm biology and ecology during the overwintering seasons. Here, I investigated seasonal changes in yellow perch (Perca flavescens) biology, ecology and ecotoxicology over a one-year period in Lake Manganese. Significant seasonality was observed for metrics including fish energy densities (kJ/g), gonadosomatic indices, whole-body lipid contents, and carbon stable isotope values (δ¹³C). …

On Site Comparison Of The Osha 42, Asset Ez4-Nco, Iso-Chek, Dan And Cip10 Methods For Measuring Toluene Diisocyanate (Tdi) At A Polyurethane Foam Factory, Simon Aubin, El Mekki Hamdi, Audrey Joly, Philippe Sarazin, Jacques Lesage, Livain Breau, Mark Spence, Sébastien Gagné

Études primaires

Because of the semi-volatile nature of diisocyanates (being airborne in both physical vapor and particulate phases), their high reactivity and low occupational exposure limits, diisocyanate exposure evaluation has been challenging for industrial hygienists and laboratories. The objective of this study was to compare the toluene diisocyanate (2,4 and 2,6 isomers, TDI) concentration measured by five methods in a flexible polyurethane foam factory using different collection or derivatization approaches. The methods used were: OSHA 42 modified (filter, 1-(2-pyridyl)piperazine) (OSHA), Asset EZ4-NCO (denuder and filter, dibutylamine) (Asset), Iso-Chek (double-filter, 9-(N-methylaminomethyl) anthracene and 1,2-methoxyphenylpiperazine), DAN (filter, 1,8-diaminonaphthalene), and CIP10 (centrifugation, 1,2-methoxyphenylpiperazine). Particle real-time …

On-Site Comparison Of The Osha 47, Asset Ez4-Nco, Iso-Chek, Dan, And Cip10 Methods For Measuring Methylene Diphenyl Diisocyanate (Mdi) At An Oriented-Strand Board (Osb) Factory, Simon Aubin, El Mekki Hamdi, Audrey Joly, Philippe Sarazin, Jacques Lesage, Livain Breau, Mark Spence, Sébastien Gagné

Études primaires

Diisocyanates are occupational contaminants and known sensitizers causing irritation (skin and respiratory tract) as well as occupational asthma. Because of their physicochemical properties (semi-volatile and high reactivity) and low occupational limits, diisocyanate exposure evaluation is still a challenge nowadays for industrial hygienists and laboratories. The objective of this study was to compare the methylene diphenyl diisocyanate (MDI) concentrations measured by five methods using different collection or derivatization approaches in an oriented-strand board (OSB) factory. The methods used were: OSHA 47 (filter, 1-(2-pyridyl)piperazine) (OSHA), Asset EZ4-NCO (denuder and filter, dibutylamine) (Asset), Iso-Chek (double-filter, 9-(N-methylaminomethyl) anthracene and 1,2-methoxyphenylpiperazine), DAN (filter, 1,8-diaminonaphthalene), and …

Development Of Novel Analytical Methods For Detection And Determination Of Tamoxifen In Oral Fluid And Discrimination Between Regioisomeric Aromatase Inhibitors For Doping Control Purposes, Brooke A. Sutton

Online Theses and Dissertations

The use of SERMs (Selective Estrogen Receptor Modulators) – most notably the drug Tamoxifen – has significantly increased among athletes over the past decade to enhance athletic performance and/or negate certain side effects of using anabolic steroids. This “doping” is always banned by WADA (World Anti-Doping Agency) for all athletes, but SERMs can naturally increase testosterone production so they are a tempting alternative to using steroids or androgenic supplements that can cause significant health problems (e.g. acne, breast development, frequent urge to urinate, low libido, etc.). Similarly, the use of AIs (Aromatase Inhibitors) has also increased among athletes for identical …

Environmental Contaminants, Parasitism, And Neoplasia In White Perch Morone Americana From Chesapeake Bay, Usa, Mark Arnold Matsche

Graduate Theses, Dissertations, and Problem Reports (ETD)

White perch are an abundant demersal fish species in freshwater and oligohaline habitats of the Chesapeake Bay. An avoidance of salinity > 12-15 ppt generally restricts the distribution and movements of fish to within tributaries in the mid to lower Bay, which over time has resulted in the formation of at least three separate stocks in Chesapeake Bay. Sub-populations of white perch that are partially isolated may serve as sentinels of the conditions or stressors in the tributaries in which they reside. Fish are exposed to a variety of environmental contaminants and other anthropogenic stressors that can vary in magnitude based …

Non-Invasive Method For Leptin Supplementation In Zebrafish (Danio Rerio), Regan Mcnamara

Williams Honors College, Honors Research Projects

I tested the hypothesis that recombinant leptin protein can be introduced to zebrafish in vivo through non-invasive soaking in a solution containing the protein. One way to study various molecules’ effects in vivo is through intraperitoneal or intracerebroventricular injections during the embryonic or larval stage, which is invasive, difficult to administer, and can have a high mortality rate. 48 hours post fertilization (hpf) zebrafish were soaked in a His-tagged recombinant leptin protein solution at 10 nM and 100 nM concentrations (produced by Genscript). After soaking, zebrafish larvae were washed extensively to remove all recombinant protein on their exterior before homogenization. …

Development Of A Method For The Detection And Quantification Of Various Benzodiazepines And Z-Drugs In Human Blood And Qualitative Identification In Urine Samples Using Liquid Chromatography Mass Spectrometry (Lc-Ms/Ms), Haley Michel

Williams Honors College, Honors Research Projects

This method developed in the toxicology department at the Cuyahoga County Medical Examiner’s Office (CCMEO) detects 40 benzodiazepines and metabolites along with several z-drugs in blood and urine by liquid chromatography tandem mass spectrometry. A sample amount of 0.5 mL was used to detect analytes in postmortem drug facilitated sexual assault and impaired driving cases. Twenty-nine analytes met criteria for quantification while the remaining 14 were used as qualitative indicators. Bias and precision results for quality controls met criteria, staying within ±15% except for clonazolam and etizolam which were within ±20%. Quantitative reporting criteria which included dilution integrity was met …

Exosomes As Systemic Mediators Of Nanotube Induced Neurotoxicity, Christopher G. Canal

Theses and Dissertations

Extra-pulmonary effects of nanoparticle inhalation have been well documented; however, mechanisms for conveying peripheral bioactivity remain elusive. Recent studies point to indirect molecular mediators shed into the circulation. Protein and lipid alternatives to cytokines or chemokines have been proposed, yet the diversity among responses suggests a broader assemblage of factors. Recently we have proposed proteolytic fragment peptides as an additional source of bioactivity, which interestingly were significantly associated with exosomal proteins after enrichment analysis. Here we tested whether modeled exposure to multi-walled carbon nanotubes (MWCNT) could alter the composition and bioactivity of circulating exosomes. Male C57BL/6 mice were exposed by …

The Combined Effects Of Chemicals Used In Textile Processing On Plankton Communities., Diana Wilson

Honors College Theses

Industrial discharge, such as textile effluent, is a major source of chemical mixtures to surface waters. The effects of these mixtures on interacting aquatic organisms can be difficult to predict. We hypothesized that individual chemical effects on phytoplankton and a zooplankton grazer are altered by the presence of other chemicals in mixtures. Microcosms containing a phytoplankton food source (Chlorella sp.) and a zooplankton grazer (Daphnia magna) were exposed to THPC, ammonium, and hydrogen peroxide in a fully crossed design in a greenhouse for one week. Phytoplankton abundance was quantified and zooplankton response was measured as mortality and …

Surfacant Contamination Alters Freshwater Phytoplankton Community Composition, William H. Hodge

College of Graduate Studies: Theses & Dissertations

Pollution from cleaning and personal care products enter freshwater systems and have the potential to alter phytoplankton abundance and diversity. Alkyl polyglucoside (APG), a widely used foaming agent in detergents, decreases phytoplankton abundance, but whether sensitivity to APG is affected by taxonomic identity and/or the presence of competitors is unclear. Establishing taxon-specific responses to APG is important, because taxa differ in nutritional quality and palatability for zooplankton grazers.

Chapter one describes comparisons between how individual phytoplankton communities respond to the same range of APG concentrations to test hypotheses that: 1) chemical concentration determines how individual taxa respond to APG; 2) …

The Exploration Of Nanotoxicological Copper And Interspecific Saccharomyces Hybrids, Matthew Joseph Winans Phd

Graduate Theses, Dissertations, and Problem Reports (ETD)

Nanotechnology takes advantage of cellular biology’s natural nanoscale operations by interacting with biomolecules differently than soluble or bulk materials, often altering normal cellular processes such as metabolism or growth. To gain a better understanding of how copper nanoparticles hybridized on cellulose fibers called carboxymethyl cellulose (CMC) affected growth of Saccharomyces cerevisiae, the mechanisms of toxicity were explored. Multiple methodologies covering genetics, proteomics, metallomics, and metabolomics were used during this investigation. The work that lead to this dissertation discovered that these cellulosic copper nanoparticles had a unique toxicity compared to copper. Further investigation suggested a possible ionic or molecular mimicry …

In Vitro Assessment Of Deleterious Impacts Of Organomodified Nanoclays And Their Incinerated Byproducts On Human Cells, Andrew Philip White

Graduate Theses, Dissertations, and Problem Reports (ETD)

Organomodified nanoclays (ONCs: i.e., smectite clays with different organic coatings), act as nanofillers in applications ranging from automotive, to aerospace, and biomedical implementations. Because of their large utilization, ONC industry is projected to be a U.S. $3.3 billion industry by 2023. However, emerging studies showed that ONCs and ONC-nanocomposites could harbor health risks upon pulmonary exposure and along their life cycle, namely during synthesis, handling, use, manipulation, and disposal. Specifically, the potential for exposure and adverse effects on human health primarily includes release of dry particulate during handling, manipulation, release during use, and release during the end-of-life disposal or recycling …

Phytoremediation Potential Of Four Heavy Metals In Soil By Chromolaena Odorata (L.) King & Robinson At The Phytotoxicity Screening Benchmarks, Gloria O. Omoregie, Beckley Ikhajiagbe, Geoffery O. Anoliefo

Tanzania Journal of Science

The remediative capacity of Chromolaena odorata with respect to heavy metal induced growth-stress was investigated. This was with a view to providing information on the adaptive mechanisms adopted by the test plant during the phytoremediation of selected heavy metals such as copper, manganese, zinc and cadmium. Stems of C. odorata were planted in soils polluted with  Mn, Zn, Cd, and Cu at the ecological screening benchmark (ESB) of 50 mg/kg (Mn and Zn), 4 mg/kg (Cd) and 100 mg/kg (Cu) of metal per kilogram of soil, in varying concentrations of 0 ESB (control), 1 ESB, 3 ESB and 5 ESB. …

Acute Exposure To Tcdd Increases Liver Disease Progression In Mice With Carbon Tetrachloride-Induced Liver Injury, Giovan N. Cholico

Boise State University Theses and Dissertations

Liver disease is a worldwide problem and the 9^th leading cause of death in the United States. Common causes of liver disease include alcohol abuse, virus infection, and nonalcoholic fatty liver. Regardless of etiology, liver damage elicits inflammation and drives the activation of hepatic stellate cells (HSCs), which deposit collagen throughout the liver. During chronic injury, excessive collagen deposition, referred to as fibrosis or “scarring”, can progress to cirrhosis, cancer, and organ failure. Emerging evidence indicates a strong association between liver disease and exposure to environmental chemicals. This research investigated mechanisms by which exposure to the environmental contaminant 2,3,7,8-tetrachlorodibenzo- …

Effects Of Mercury On The Dopamine Transporter Cell Surface Expression In Pc12 Cells, Christina Hui

Student Theses

Environmental factors, such as heavy metal exposures, have been suggested to have an impact not only on neurodegenerative disease, such as Parkinson’s disease, but also on psychostimulants abuse and their toxicity. In this study, two questions were addressed: 1) effects of mercuric chloride on parkinsonian toxicant 1-methyl-4-phenylpyridinium (MPP⁺) induced cytotoxicity and 2) effects of mercuric chloride on cell surface dopamine transporter. Pheochromocytorma cells (PC12) were treated with various concentrations of mercuric chloride (0.02~2.0 ppm) for 4 hours with and without 0.1 mM MPP⁺. Significant potentiation of toxicity was observed when there was co-treatment with 0.5 ppm …

Amélioration De La Justesse Des Modèles D’Hygiène Du Travail Utilisés Pour Estimer Des Expositions Professionnelles À Des Vapeurs De Solvants, Spéro Abattan, Stéphane Hallé, Daniel Drolet, Ali Bahloul, Patrick Eddy Ryan, Wejden Chouchene, Carlos Castro Ruiz, Jérôme Lavoué, Maximilien Debia

Rapports de recherche scientifique

Chaque année, des travailleurs québécois subissent des effets sur leur santé après avoir été exposés à des substances chimiques, notamment à des solvants. La modélisation des expositions professionnelles occupe une place importante dans la prévention des risques. Cette recherche vise à étudier différents aspects de la modélisation pour estimer des expositions professionnelles à des vapeurs de solvants dans le but d’en améliorer la justesse de prédiction. Le travail de recherche a été effectué en deux volets. Grâce à la mise en œuvre de tests à petite échelle (volet I) et à échelle humaine (volet II), les travaux présentés dans cette …

The Role Of Omega-3 Polyunsaturated Fatty Acids In Blood Pressure Regulation And Secondhand Smoke-Induced Vascular Dysfunction, Emily Anna Wheeler

Biomedical Sciences ETDs

Omega-3 polyunsaturated fatty acids (n-3 PUFAs) may lower cardiovascular disease risk by reducing blood pressure (BP). We hypothesized that fat-1 transgenic mice, which convert n-6 PUFAs to n-3 PUFAs, would have improved vascular function in BP regulation and following secondhand smoke (SHS) exposure, compared to wild type (WT) mice.

BP was recorded in mice fed an n-6 PUFA, or standard chow diet. On the n-6 PUFA diet fat-1 mice had a lower mean arterial pressure and a greater decrease in diastolic BP when treated with an ACE inhibitor, compared to WT mice. No differences were observed on the chow diet. …

Sustainable Solutions, Fall/Winter 2020, Issue 41

Sustain Magazine

No abstract provided.

Qualitative Approach To Comparative Exposure In Alternatives Assessment, William Greggs, Thomas Burns, Peter Egeghy, Michelle R. Embry, Peter Fantke, Bonnie Gaborek, Lauren Heine, Olivier Jolliet, Carolyn Lee, Derek Muir, Kathy Plotzke, Joseph Rinkevich, Neha Sunger, Jennifer Y. Tanir, Margaret Whittaker

Public Health Sciences Faculty Publications

Most alternatives assessments (AAs) published to date are largely hazard-based rankings, thereby ignoring potential differences in human and/or ecosystem exposures; as such, they may not represent a fully informed consideration of the advantages and disadvantages of possible alternatives. Building on the 2014 US National Academy of Sciences recommendations to improve AA decisions by including comparative exposure assessment into AAs, the Health and Environmental Sciences Institute's (HESI) Sustainable Chemical Alternatives Technical Committee, which comprises scientists from academia, industry, government, and nonprofit organizations, developed a qualitative comparative exposure approach. Conducting such a comparison can screen for alternatives that are expected to have …